| 摘要 |
<p>A rotary joint of the present invention maintains cryogenic temperature of a supplying refrigerant flowing through a fluid passage, and makes available to lubricate a seal face by the supplying refrigerant as well as to minimize a running cost for the refrigerant. The rotary joint of the present invention is that, in a mechanical seal device (1) composed of a mechanical seal comprising spaced rotary seal rings (1A) having a seal face (1A1) at both end faces tightly sealed with an outer circumferential face of a vacuum use cylindrical shaft (10), stationary seal rings (2A) provided with a counter seal face (2A1) hermetically sealed with the seal face (1A1) provided at both sides of the rotary seal rings (1A), elastic bellows (2B) which contact with a tip end circumferential face of the stationary seal ring (2A) for pressing the rotary seal ring (1A) to the seal face (1A1) side, wherein a first vacuum passage (50A1) communicates through a first clearance vacuum passage which is through an inner circumference of the counter seal face (2A1) of the stationary seal ring (2A) between an inner circumferential face of the stationary seal ring (2A) at one tip end side of the mechanical seal device (1) and the vacuum use cylindrical shaft (10), a second vacuum passage (50B1) communicates through a second clearance vacuum passage which is through an inner circumferential face of the stationary seal ring (2A) at another tip end side of the mechanical seal device (1) and the vacuum use cylindrical shaft, the first vacuum passage (50A1) and the second vacuum passage (50B1) are vacuumized so as to suck an inner circumferential side of the counter seal face (2A1) of the stationary seal ring (2A) of the one tip end side and an inner circumferential side of the counter seal face (2A1) of the stationary seal ring (2A) of the another tip end side.</p> |
